Heat exchanger



.OOOQb 90 oOOOoJ &f W000 N. WYNDHAM ET AL HEAT EXCHANGER Filed Feb.

HTTOXM/f) "Patented Sept. 22, 1931 JAMES WYNDHAI AND STEPHEN LEYSHON WYNDHAH, OF CARDIFF, WALES HEAT EXCHANGER Application fled Iebrnary 1a, 1929, Serial 110. 839,684, and in Great Britain lay 11.1928.

. .lo ing fluid and preferably wherein the heated fluid is split up by mechanical means and 1 im inged on to the conducting surface.

ince such a heat exchanger is particularly adapted for use as a feedwater heater or evaporator heater in connection with marine boilers, the conductor is continually subjected to the depositation of brine and other impurities which impair the efficiency of the heat exchanger. In addition the con 2o ductor is subjected to a wide range of temperatures on its opposite side.

These disadvantages make it desirable that the heat exchanger be constructed to minimize possible losses arising from them.

According to this invention therefore, a heat exchanger of the kind referred to comprises three concentric tubular members characterized by the fact that the intermediate or conducting member of the heat exchanger is arranged therein with an expansion joint which can be readily broken to facilitate removal of the conductor.

The distributor may be in the form of a perforated or grid-like member dividing the aforesaid heating space into an inflow pas; sage and an outflow passage, which communicate with one another solely through the perforations. lVith this arrangement the heating fluid admitted to the heater is broken up into numerous small streams all directed to impinge against the conducting surface, whereafter they re-unite and flow in contact with or in close proximity to said surface.

Preferably the passages are circular and the outflow passage surrounds the inflow passa e and is itself surrounded by the passsa e or the flow of the medium to be heated. e will now describe our invention, with :3 reference to the accompanying drawings which illustrates an embodiment of a feed water heater, the heatin fluid being steam.

Fig. 1 1s a longitudina sectional view of a heat exchanger utilized as a feed water heater.

Fi 2 is a sectional view taken on the line 11- I of Fig. 1.

In the figures like references refer to like parts.

The apparatus comprises three concentric tubular members 1, 2, 3 disposed one within the other'to form three concentric passages l, 2, 3 (Fig. 2). The passage 5 forms the inlet for the heating fluid (steam in this case) tothe interior of the innermost tubular member 1. At one end the outer tubular member 3 1s outwardly flanged to form a seat for the outward flange of the intermediate tubular member 2.

At the other end the outer tubular member 3 is inwardly flan ed at 3" to form a seat for the cap 10. The lntermediate member 2 is internally threaded at 2 to en a e a correspondingly screwed part 6 0 t e nozzle member 6 provided with the outlet 6 for the heatmg fluld. This nozzle member has a reduced portion 6 passing through the cap 10 in which a gland 11 is inserted. Both the cap 10 and the gland 11 have smooth bores to permit the longitudinal expansion of the intermediate member 2.

The inner tube is closed at the end opposite the inlet and its walls are perforated as at 7 to enable the steam from tube 1 to escape by way of the perforations into passage 2, impinging on the wallsof the tube 2. The heat ,from the steam is communicated by the walls of the'tube 2 to the medium to be heated (feed water in this case) which enters the passage 3" by the inlet 8, and leaves it by the outlet 9.

Steam admitted to the interior of the inner tubular member 1 flows radially through the holes or perforations, and by means of this alteration in the direction of flow, comes into intimate contact with the conducting walls of the tube 2.

Owing to the provision of the perforations in the inner tubular member 1, the heating fluid, instead of simply traversing the apparatus as a substantially uniform stream only the peripheral layer of which contacts with the heat exchanging or conducting surface, is

broken up into numerous small streams all of 5 which impinge on said surface. These streams thereafter re-unite the flow towards the outlet still in contact with, orin close proximity to, said surface, whereby very eflicient exchange of heat is obtained.

When used as a feedwater heater for a steam power installation the device is inserted in the exhaust pipe line between the low pressure cylinder and the condenser so that the exhaust steam will pass through the aforesaid inflow and outflow passages to the condenser, and the inlet and outlet on the outer tubular member of the heater are coupled to the feedwater supply so that the feedwater delivered by the feed pumps will pass 20 through the outer passage of the heater to the boiler and will be heated by the exhaust steam in the manner already described.

In practice there will be a considerable length of pipe including one or more bendsconnecting the outlet 6 to the hot well. which can easily expand and contract without disturbing its connections, to take up the expansion and contraction of the intermediate tube 2.

3D The intermediate member 2 together with the innter tube 7 can be readily removed for cleaning as and when necessary by simply unscrewing said member from the nozzle member 6 of the expansion joint, and disconnecting the end of the heater from the exhaust conduit and disconnecting the outer casing 3 from the supply line. When thus removed access can be had to the interior and exterior of all three tubular members 1, 2, 3.

4n Modifications may obviously be made without departing from the scope of the invention. For example, instead of arranging the passage for the medium to be heated so that it surrounds the space: (inflow and outflow passages) for the heating fluid, the arrangement may be reversed, in which case the intermediate member in the form of the invention herein before described would be perforated and the inner member made open- 0 ended to afford a through-passage for the medium to be heated.

The heating fluid and the medium to be heated may be made to traverse the heater in opposite directions, or in the same direction, as preferred, or as found most suitable according to the particular purpose for which the heater is used.

A heater in accordance with the invention is simple to construct, easy to install, efficient in operation, and easy to maintain.

While we have described the heat exchanger above as applied principally to a heater, it is to be understood that the device can be used as a cooler or condenser for the medium referred above as the heating medium.

lVhat we claim as our invention and desire to secure by Letters Patent is 1. A heat exchanger, preferably for use as a boiler feedwater heater, comprising, in combination, a tubular casing with inlet and outlet connections, an inner tubular member and an intermediate tubular member projecting concentrically into said casing from one end thereof, flanges for said members at said end, a nozzle member projecting through the opposite end of said casing to constitute a severable joint for the proximate end of said intermediate member, and means co-acting with said nozzle member to form an expansion joint said inner tubular member being supported at one end only and being substantially shorter than said casing.

2. A heat exchanger, particularly for use as a boiler feedwater heater, comprising, in combination, a tubular casing with inlet and outlet connections, a perforated inner tubular member and an intermediate tubular memher projecting concentrically into said casing from one end thereof, flanges for said members at said end, a nozzle member projecting through the opposite end of said casing to constitute a severable joint for the proximate end of said intermediate member, and means co-acting with said nozzle member to form an expansion joint said inner tubular member being supported at one end only and being substantially shorter than said casing.

3. A heat exchanger, particularly for use as a boiler feedwater heater, comprising, in combination, a tubular casing with inlet and outlet connections, an inner tubular member and an intermediate tubular member projecting cdncentrically into said casing from one end thereof said intermediate member being screw-threaded at its inner end, flanges for said members at their outer ends, a nozzle member projecting through the opposite end of said casing and having a screw-threaded portion for the attachment of the corresponding screw-threaded inner end of said intermediate member, and means co-acting with said nozzle member to form an expansion joint.

4. A heat exchanger, particularly for use as a boiler feedwater heater, comprising, in combination, a tubular casing with inlet and outlet connections, a perforated inner tubular member and an intermediate tubular member projecting concentrically into said casing from one end, said intermediate member being screw-threaded at its inner end, flanges for said members at their outer ends, a nozzle member projecting through the end of said casing opposite the end where said intermediate member projects into said casing said nozzle having a screw-threaded portion for the attachment of the corresponding screwthreaded inner end of said intermediate member, and means comprising a gland cacting withsaid nozzle member to form an expansion joint.

In testimony whereof we aflix our signatures.

JAMES NEWBY WYNDHAM. STEPHEN LEYSHON WYNDHAM. 

